This project helps investigators to cope with complex equations that model biological systems. A model of HIV infection kinetics has been developed and tested to explain oscillating population sizes in simple infection experiments (with John Spouge, NLM, and Dimiter Dimitrov). A final paper is in preparation on the kinetics of cytochrome aa3 (with R.W. Hendler and S. Bose). Magnetic resonance (MR) imaging gradient sequences are being developed that will optimize the resolution of anisotropic diffusion (AD) images. We have proved that at least seven MR images are required to produce a single AD image (with Peter Basser, NCRR). Recipes for generating experimental designs are being developed that will optimize the resolution of exponential processes in MR imaging (with R.G.S. Spencer, NIA, and George Weiss, PSL). Confidence limits on certain ratios of probabilities in paired dichotomous data are being investigated. This work relates to whether one medical test is superior to another. (with Jun-Mo Nam, NCI, Mark VanRaden, NIAMD, William Blackwelder, NIAMD, and David Van Sant, DCRT). A major upgrade of MATLAB, a popular numerical software package, has prompted a major effort on my part to learn it, and to teach it in the DCRT training program. I have been teaching MATLAB in its various incarnations for over a decade at DCRT.